After struggling with splitting one physical monitor into two or more virtual monitors myself, I feel I can summarize the answer into two "tools" that can both be be used to create the configuration that works best for a particular workflow.
There are two-main methods - software-based virtual monitors and hardware-based picture-by-picture (BPB). PBP is only available via the monitor so I recommend folks purchase monitors with BPB functionality and appropriate # of ports, so they have this option.
- Virtual monitors. Recommended use: Gaming, video editing, software development, etc. but light office work. With this solution, a monitor can be split into any combination of virtual monitors.
However, this solution does not work well with desktop sharing via business communication software/videotelephony (e.g. Zoom, MS Teams, Webex, Google Meet, etc.) To enable desktop sharing with virtual monitors a user must mirror their virtual monitor to a window. The window is then shared via the communications software, rather than a real desktop. This mirroring is done in software so users should have a really good cpu/gpu or otherwise they’ll have performance issues. The mirroring is done via a polling interval. This is usually configurable. This polling interval can cause image lags if it can’t be adjusted. Shorter interval affects CPU/GPU. If a user also wants to record desktops with software such as OBS (Open Broadcaster Software) they will also require this method which is not ideal.
Examples of virtual monitor software are: DisplayFusion, Matrox PowerDesk, MaxTo (formerly WinSplit Revolution), UltraMon, Microsoft PowerTools FancyZones (free) and Actual Multiple Monitors.
- Picture-by-Picture (PBP). Recommended use: Heavy office work - multiple meetings, screen sharing, recording of meeting sessions, etc. It allows a user to display two video sources; in effect, two displays in one physical display.
PBP is a feature of the monitor - so the user needs a monitor that supports it. PBP splits the monitor equally into two and requires a physical cable from the PC to the monitor for each “display” - so it requires two cables (This also means the monitor must support two cables).
This is especially ideal for office work with ultrawide monitors. An ultrawide monitor split into two virtual monitors can save space on the desk versus two physical monitors. For example, two 16:9 displays can be replaced by a single 43:18 display split into two displays of 25:21 (roughly an office aspect ratio of 5:4 or 4:3) which saves about 1 foot of physical desktop space (width).
Other advantages: 1. enables users to take ergonomic advantage of curved displays. 2. Saves power. 3. For an IT department, would reduce the number of assets to manage.
Note: PBP implementations may suffer from "Input Auto Switch" features which creates a mirroring situation. Workarounds include disabling this feature and/or manually switching the primary input source.
There are also video splitters/wall contollers which allow a display to be mirrored to another monitor(s) - I didn't find this useful in my use-case. There are also dummy plugs which fool the graphics card into thinking there is another monitor. But the display doesn’t know about it, so the only way to view that source, without manually switching (which you could do if you plugged into a second port in the monitor), is by using something like OBS to view that image source in a window. This might be useful if a user has static windows that they leave up, like security cameras. Dummy plugs are typically used by hosts with no displays to enable RDP or other remote program to remote connect to it without needing a physical monitor.
A good reference site which discusses the two tools: https://www.orei.com/blogs/news/can-you-split-an-ultrawide-monitor-into-two-screens